Undefined symbol _bfdec_normalize_and_round, when compiling without CONFIG_BIGNUM, since 94010ed

[past-due]

In 94010ed, the defines for USE_BF_DEC and USE_FFT_MUL were placed inside an #ifdef CONFIG_BIGNUM:

quickjs/libbf.c

Lines 40 to 45 in 94010ed

	#ifdef CONFIG_BIGNUM
	/* enable it to use FFT/NTT multiplication */
	#define USE_FFT_MUL
	/* enable decimal floating point support */
	#define USE_BF_DEC
	#endif

This causes an undefined symbol error when compiling without CONFIG_BIGNUM defined, due to _bf_atof_internal's referencing _bfdec_normalize_and_round.

ld: Undefined symbols:
  _bfdec_normalize_and_round, referenced from:
      _bf_atof_internal in libquickjs.a[3](libbf.o)

(Example: Try compiling QuickJS without optimizations and without CONFIG_BIGNUM defined.)

It appears that there are only two uses of _bf_atof_internal when CONFIG_BIGNUM is undefined:

quickjs/libbf.c

Lines 3159 to 3172 in 3bb2ca3

	int bf_atof2(bf_t *r, slimb_t *pexponent,
	const char *str, const char **pnext, int radix,
	limb_t prec, bf_flags_t flags)
	{
	return bf_atof_internal(r, pexponent, str, pnext, radix, prec, flags,
	FALSE);
	}
	int bf_atof(bf_t *r, const char *str, const char **pnext, int radix,
	limb_t prec, bf_flags_t flags)
	{
	slimb_t dummy_exp;
	return bf_atof_internal(r, &dummy_exp, str, pnext, radix, prec, flags, FALSE);
	}

Both of these pass FALSE to the BOOL is_dec parameter of _bf_atof_internal, and so _bfdec_normalize_and_round should never actually be called when CONFIG_BIGNUM is undefined:

quickjs/libbf.c

Lines 3105 to 3108 in 3bb2ca3

	if (is_dec) {
	a->expn = expn + int_len;
	a->sign = is_neg;
	ret = bfdec_normalize_and_round((bfdec_t *)a, prec, flags);

---

So it seems like _bf_atof_internal could use an #ifdef USE_BF_DEC check around this single use of bfdec_normalize_and_round. For example (not sure if this is the best / desired approach):

      if (is_dec) {
+ #ifdef USE_BF_DEC
          a->expn = expn + int_len;
          a->sign = is_neg;
          ret = bfdec_normalize_and_round((bfdec_t *)a, prec, flags);
+ #else
+         // bfdec_normalize_and_round not available without USE_BF_DEC
+         // if (!radix_bits)
+         //    bf_delete(a); // needed?
+         bf_set_nan(r);
+         ret = BF_ST_MEM_ERROR;
+ #endif
      } else if (radix_bits) {

@chqrlie : Any thoughts / suggestions?

[chqrlie]

@past-due Sorry for the lack of responsiveness, I shall fix it this week.